title: Modelling the effect of minor orthopaedic day surgery on patient mood at the early post-operative period: a prospective population-based cohort study.
abstract: OBJECTIVE
  The effect of minor orthopaedic day surgery (MiODS) on patient's mood.
  
  
  METHODS
  A prospective population-based cohort study of 148 consecutive patients with age above 18 and less than 65, an American Society of Anaesthesiology (ASA) score of 1, and the requirement of general anaesthesia (GA) were included. The Medical Outcomes Study - Short Form 36 (SF-36), Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) were used pre- and post-operatively.
  
  
  RESULTS
  The mean physical component score of SF-36 before surgery was 45.3 (SD=+/-10.1) and 8 weeks following surgery was 44.9 (SD=+/-11.04) [n=148, p=0.51, 95% CI=(-1.03 to 1.52)]. For the measurement of the changes in mood using BDI, BAI and SF-36, latent construct modelling was employed to increase validity. The covariance between mood pre- and post-operatively (cov=69.44) corresponded to a correlation coefficient, r=0.88 indicating that patients suffering a greater number of mood symptoms before surgery continue to have a greater number of symptoms following surgery. When the latent mood constructs were permitted to have different means the model fitted well with chi(2) (df=1)=0.86 for which p=0.77, thus the null hypothesis that MiODS has no effect on patient mood was rejected.
  
  
  CONCLUSIONS
  MiODS affects patient mood which deteriorates at 8 weeks post-operatively regardless of the pre-operative patient mood state. More importantly patients suffering a greater number of mood symptoms before MiODS continue to have a greater number of symptoms following surgery.
authors.affiliation: Maudsley Hospital & Institute of Psychiatry, King's College London, London SE5 8AF, UK. etsiridis@doctors.org.uk
authors.forename: Evangelia M
authors.initials: EM
authors.lastname: Tsapakis
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Tsiridis
authors.forename: Alistair
authors.initials: A
authors.lastname: Hunter
authors.forename: Zakareya
authors.initials: Z
authors.lastname: Gamie
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Georgakarakos
authors.forename: Panos
authors.initials: P
authors.lastname: Thomas
authors.forename: Constantin
authors.initials: C
authors.lastname: Schizas
authors.forename: Robert M
authors.initials: RM
authors.lastname: West
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000706:statistics & numerical data*; D001008:Anxiety Disorders / Q000175:diagnosis; D015331:Cohort Studies; D003866:Depressive Disorder / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013511:Minor Surgical Procedures / Q000706:statistics & numerical data*; D008960:Models, Psychological; D019964:Mood Disorders / Q000175:diagnosis*; D019637:Orthopedic Procedures / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000175:diagnosis; D011184:Postoperative Period; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D055815:Young Adult